Sunburn Monitor is a UV monitor with sound-based indication. It calculates the max sun exposure before sunburn based on your skin type.
The project was published over hackaday.io by [Quarterturn].
It’s based around SI1132 light sensor from Silicon Labs. SI1132 is a UV index and ambient light sensor with I2C interface and it’s available in 10-lead 2×2 mm QFN package. Sunburn Monitor uses ATMEGA168 MCU where the firmware was developed using Arduino environment.
The design has a protection transistor Q1 (DMP2035U-7) in the input, we covered in a past blog how to protect you circuit from reverse voltage, and Q2 is used to enable/disable the supply voltage of the sensor.
Sunburn Monitor powered by a 3v CR2032 battery with power management relies primarily on either deep sleep via hardware interrupt or watchdog timer interrupt for sleep-wake-sleep monitoring cycles, according to [Quarterturn].